Bearing for electrical condensers



Sept. 22, 1931. T. J. SCOFIELD V 1,324,304

- BEARING FOR ELECTRICAL CONDENSBR Filed NOV. 9, 1929 .9" f f j WW I IGD as w (H) (ID 11) GD 11) m m J Tb okiii'iifc'i/w BYQZW. W

' ORNEY 5 the rotor plate and .10 rotor shaft and the 2.) shown in Fig.3.

as in Fig. 1.

Patented Sept. 22, 1931 UNITED STATES PATENT OFFICE maonona I, seem, or

JACKSON. IICKIGAN, ASSIGHOi 1'0 TEE SPARKS- WITHINGIOII comm, ACORPORATION 01' OHIO m 103 ELECTRICAL ooxmms'aas Application lledIevsnber 0, ma. lerlal Io. 406,80.

This invention relates to electrical gang condensers such as are used inradio sets.

One of the objects of the invention is to co struct the bearings of thecondenser so that shaft assembly can be readily placed in position.

Another object of the invention is to construct the bearin contacts sothat there will be good electrica spring contact between the frame ofthe condenser.

Another object is to arrange the hearing so that there is continualposition regardless of jars or vibrations to 15 which it may besub'ected while in use.

:0 used in radio sets.

' Fig. 2 is an end view of the condenser frame as viewed from the ri htof Fig. 1. I Fig. 3 is a view of t e bearing plate.

Fig. 4 is an end view of the bearing plate Fig. 5 is an elevation of thecompression plate of the bearing. 5

- Fig. 6 is a view of the condenser with the shaft and rotor assemblybeing. placed" in a? position.

Fig. 7 is a horizontal section view of the right-hand end be as shown inFig. 1. Fig. 8 is a view of t e spring contact for the left-hand endoftherotor shaft as shown Fi 9 is a lo 'tudinal section taken on the lnes A-A 0 Fig. 8.

"Gang condensers used in radio sets are precision instruments and themechanical v4o movement of the rotor plates in respect to the statorplates must be correct or else "undesired variations in capacity or evenshortcircuits will result. It is necessary to have the rotor shaftrevolve in a snug fittin bear- 6 ing at'eachend for this reason. It isalso necessary to have good electric contact between the rotor shaft andthe frame of the condenser to conduct the signal currents.

To permit the ready insertion of the rotor 50 in the condenser one ofthe bearings of the frictional pressure to insure that the rotor willstay in the adjusted upwardly awa makes a smooth fit with the rotorshaft.

screws to compress the springs and rotor shaft is made separate from theframe of the condenser. The shaft 1 of the rotor has flange or sidebearin member 2 thereon near one end, as shown 0 earl in Figs. 6 and 7.A hole 3 is formed. in t e end member 5 4 of the condenser framesuflicientl large to rmit insertion of the shaft and t is flange 2 whenthe rotor assembly is inclined at a considerable angle such as shown inFig. 6, for exam le. 0 bearing contact is made with this ole 3 and thesize of such hole is immaterial so long as it is large enou h to permitthe flange 2 to be inserted wit the rotor plates clearing the statorplates.

When the rotor shaft is assembled in the a rotor bushings 5 a fibrewasher 6 may be placed on the inside of the flange 2.

The rotor assembly is pushed to the right, as shown in Fi 6 sutlicientlyto permit the end 8 of the she t to enter a snu bearin hole 1 9 in theend 10 of the con enser rame. While this operation is being performedthe rotor plates would be positioned to project from the stator plates,as shown in the rawings.

The fibre washer 7 maythen be pushed on the right-hand end of the shaft1, and brass bearing plate 11-is slipped over this end of the shaft. Thehole in this bearing late so plate 11 is half-punched at 12 in the two 0ite corners to form protuberant dowefis 13 which fit into depressions13' into end 4 of the condenser frame. These dowels in conjunction withimpressions in-the end member peroperly line the bearin plate 11 withthe aring hole 9 to hold t e shaft in proper ition. Screws 14 are passedthrough oles 15 in the bearing plate and are threaded into the endmember 4 to'ti htly clamp the plate against the end mem r of thecondenser. 'Slotted plate 16 see Fig. 5) is dropped into position witthe slot 16' around the sha t 1. It is then slid to the I ri t, untilthe screws 14 pass through the ho es 17. Springs 18. are placed on thesescrews and nuts 19 are threaded on to the force the fibre washer 6. Withplate 16 against this arrangement the flange 2 on; shaft 1 is 101'.

I the rotor shaft and the they fer to use the drum and forced to theright b the springs and frictionally engages the bre washers 6 and 7 sothat suflicient friction is obtained to always hold the rotor shaft inany position in which it is turned while allowing suflioient freedom tomanipulate the shaft for tuning purposes. If it is necessar to removethe rotor shaft and the assemble rotor plates the operation justdescribed would be reversed.

In order to insure 00d contact between frame of the condenser aconnecting member (Fig. 8) is used. This consists of a strip of oodconducting metal such as spring brass aving a slotted opening 21 in oneend, preferably 'of oblong form, to permit adjustment and a hole 22 inthe opposite end slightly smaller than the end of the shaft 8. This holeis stam ed so as to draw a protruding ring 23 to urnish a good bearingsurface with the rotor shaft and a slot 24 is punched through this endto permit it to spring a art sufficiently to receive the end of the shat and thus furnish spring contact therewith. This member 20 is lacedover the end of the shaft 8 and the ot er end is fastened to the endplate 10 by means of screw 25 which passes through the opening 21 and isthreaded into the end plate 10.

Any form of indicating drum 26 may be i used on the other end of shaft 1and any form of rotating means may be employed. I prerotating meansshown in the applicationof Theodore J. Scofield and William D. Miner(case #2-1) Serial No. 398,864, filed October 11 1929, but I have notshown these in this application as form no part of the invention claimedin this application.

end, an

Having described my invention, what I claim is:

1. In electrical condensers, a frame, a shaft, a side-bearing flange onsaid shaft near one end, an end member on said frame havin an openingadapted to permit the entry 0 said flange and shaft at an angle thereto,a bearing member fastened to sa1d end member and fitting on one end ofsaid shaft outside of said flange, a plate fastened to said end memberand engaging the inside of said flange, and a bearing member for theother end of said shaft.

2. In electrical condensers, a frame, a shaft, a side bearing flange onsaid shaft near one end member on said frame having an opening adaptedto permit the entry of said flange and shaft at bearing fastened to saidand member and fitting on one end of said shaft outside of said flange,a plate having a slot adapted to fit over the shaft and means toresiliently clamp the said plate against the inside of said flange. v

3. In electrical condensers, a frame, a shaft, a side bearing flange onsaid shaft near one said an angle thereto, a

end, an end member on said frame having depressions and an openingadapted to permit the entry of said flange and shaft at an anglethereto, a bearing fastened to said end member and fitting on one endofsaid shaft outside of said flange and having lugs fitting in saiddepressions, a plate having a slot adapted to fit over the shaft, andmeans to resiliently clamp the said plate against the inside of saidflange.

4. In electrical condensers, a frame having a hole therein, a shaft, aflange on said shaft, said flange being small enough to enter said holeat an angle thereto, a plate fitting over said shaft on one side of sa1dframe, a plate fittin over said shaft on the other side of ame, boltspassing through said plates and frame, springs on said bolts, bearingagainst one of said plates, and nuts to compress said springs and clampsaid plates against the sides of said flange.

In testimony whereof I have signed my name to this specification this5th day of November, 1929.

THEODORE J. SCOFIELD.

